Risky Business

BY Benjamin Ryan

April 30 2010 11:00 PM ET

There are some queries that come up over and over again about what's OK to do sexually and what's not. So here's the latest word on two hot-topic transmission risks:

>Is oral sex safe? The question seems as old as Moses: Can HIV be transmitted through oral sex? Specific answers have long eluded researchers, in no small part because any evidence of risk behaviors leading to infection is self-reported and not necessarily reliable. The short answer is that oral sex is a relatively low-risk activity. Estimates on the percentage of HIV cases resulting from oral transmission vary greatly: from lower than 1% incidence, to as high as 7% in one study.

Advice to lower the risk, outside of abstaining from oral sex or using a condom, is to avoid swallowing semen and to be careful not to engage with any oral cuts or abrasions. For example, don't brush or floss shortly before or after and allow for healing time after dental work or a sore throat.

>Is there really a superbug? It's been five years since an overly alarmist New York City health department announcement about a man with an exceptionally aggressive, multidrug-resistant case of HIV set off the "superbug" scare. Fears that increasing numbers of HIVers would soon crop up with untreatable, swiftly lethal strains of the virus proved unfounded.

The Centers for Disease Control and Prevention presented new data at this year's Conference on Retroviruses and Opportunistic Infections in February that indicated 15.6% of the new HIV diagnoses in 2007 were resistant to at least one class of antiretrovirals (2% were resistant to two classes of drugs; less than 1%, to three classes.) This shows that drug resistance is often transmitted from person to person, which may complicate future treatment options.

Superinfection, also known as reinfection, in which a second strain of HIV is introduced after initial infection (possibly complicating drug regimens by broadening drug resistance), remains a common fear for many people. While the science has proved that this phenomenon has occurred in some people, it is rare, and it is most likely to occur only in the first year or two after the initial infection.